McKean said he had guessed the security credentials for the website after discovering that the default ones for phpDolphin – the particular Facebook clone used – were the predictable “admin” and “password”.

They had not been changed when setting up the website, allowing him to gain control of the service. McKean subsequently took over the advertising slots on the website with the message: “Uh, I didn’t create this site just found the login,” and a link to his Twitter page.

He told technology website Motherboard that he would possibly redirect the website to an anti-North Korean one, although on Tuesday the website was simply offline. The site was already hosting joke profiles depicting Kim Jong-Un, with several Westerners signing up.

It is unclear who had set up the service. Its web address, starcon.net.kp, suggest a link to Starcon, a South Korean technology company.

Most North Korean state websites are hosted in China rather than the country itself, which has just a few thousand internet users, out of a population of around 25 million.

Facebook, Twitter and YouTube were banned in the state last year. North Korean citizens are only able to access a limited internet but foreigners were previously able to surf the web with few restrictions.